Mogućnost primene virtualnog rotirajućeg češlja kod mehanizovanog ubiranja cvasti nevena (Calendula officinalis L.)

The objective of the investigation was to examine possibility of mechanized harvesting of marigold inflorescences by applying a virtual rotating comb type chamomile harvester. The impact of coefficient R, relation between the working device penetration into the inflorescences horizon and the average value of highest and lowest inflorescences span-width of inflorescences band, on harvest yield, was tested. It was found that for coefficient R value 1.3, in average 90 % of the inflorescences’ yield can be harvested. Future investigation should be directed towards solving the mechanical separation of the inflorescences from the harvested mass and process of shortening the inflorescences’ stems and determination of economic viability of mechanized harvest with proposed procedure.Cilj istraživanja bio je da se ispita mogućnost mehanizovanog branja cvasti primenom radnog organa tipa virtualnog rotirajućeg češlja, koji se koristi za ubiranje kamilice. Ispitan je uticaj koeficijenta R, koji predstavlja odnos dubine ulaska radnog organa u horizont cvasti i prosečne visine raspona najviših i najnižih cvasti na biljkama, na efikasnost ubiranja. Ustanovljeno je da pri veličini koeficijenta R = 1,3 može da se ostvari maksimalan udeo ukupne ubrane mase cvasti u biološkom prinosu cvasti u proseku 90 % (cvasti sa drškom dužine do 2 cm 65 % i preko 2 cm 35 %, obračunato na dužinu do 2 cm). Buduća istraživanja treba da se usmere ka rešavanju mehaničkog postupka separacije cvasti od stabljike i lišća i skraćivanja drški cvasti, kao i utvrđivanja ekonomske opravdanosti mehaničke berbe cvasti nevena prikazanim postupkom

Potencijal žetvenih ostataka uljane repice u Srbiji

Rapeseed straw is potential source of renewable energy, but important source of soil organic matter as well. The amount of crop residues, available for energy use, per hectare, is not well known. Excessive offtake of crop residues can be followed by reduction of soil fertility, removal of nutrients, organic carbon and wind erosion. The objective of the investigation was to define total and harvestable amount of crop residues – straw, and amount that remain on the field, which can be background for the calculation of soil fertility preservation. In 2013 (climatic conditions characterized as moderate dry) samples of aboveground mass of eight varieties were collected from three locations, and in 2014 (characterized as moderate to extreme humid) six varieties for one location. The samples were divided into: grain, stalks and hulls. It has been defined yield of fractions and calculated harvest index. The stalks were split along their lengths, parts measured and created cumulative mass distribution. For common harvest procedures have been defined harvestable mass, potential, for two selected cutting heights. Average harvest index was in 2013 0.34, and in 2014 lower, 0.29. Percentage of harvestable mass was between 35 and 51 % of total aboveground residual mass. Harvestable yield was in 2013 about 46 %, due to less favorable climatic conditions. This should be considered by the planning of any use of this material as energy source. It was assessed that the energy potential of rapeseed straw, including measures for preservation of soil fertility, is 1.1 to 2.0 Mg ha–1, in average. On field remained residual mass can ensure, if proper tillage is applied, protection of wind erosion and increase of soil organic matter and soil organic carbon. It is concluded that rapeseed straw can be used for soil amelioration if adequate crop rotation is applied, and can compensate offtake of residues of other crops, e.g. wheat straw and corn stover. Future investigation should be oriented toward this utilization of rapeseed straw.Slama uljane repice potencijalni je izvor obnovljive energije, ali i značajan izvor organske mase u zemljištu. Količina žetvenih ostataka, slame, koja je na raspolaganju, po hektaru, nije dovoljno poznata. Prekomerno skidanje žetvenih ostataka može da izazove negativne posledice u pogledu plodnosti zemljišta, uklanjanje nutrijenata, organskog ugljenika u zemljištu i erozije vetra. Cilj istraživanja bio je da se utvrdi ukupna količina žetvenih ostataka uljane repice, količine, koje mogu da se uberu i količine nadzemnih žetvenih ostataka, kao podloge za donošenje mera za očuvanje plodnosti zemljišta. Prikupljeni su uzorci nadzemne mase osam reprezentativnih sorti sa tri lokacije, 2013. godine (koja je bila sa umerenom sušom) i šest sorti sa jedne lokacije 2014. godine (u toku koje je bila umerena do ekstremna vlažnost). Uzorci biljaka su podeljeni na delove: zrno, stabljika i mahune. Utvrđen je žetveni indeks, prinos i relativni prinos žetvenih ostataka. Stabljike su podeljene u sekcije po visini, izmerene mase i kreiran dijagram kumulativne mase po visini. Za uobičajeni postupak ubiranja slame, presovanjem, ocenjena je količina žetvenih ostataka, koja može da se ubere za dve odabrane visine rezanja. Prosečan žetveni indeks u sezoni 2013. bio je 0,34, dok je u 2014. bio niži i iznosio je 0,29. Procenat žetvenih ostataka, koji može da se ubere bio je između 35 i 51 % od ukupne biljne mase nadzemnih žetvenih ostataka. Tehnički prinos pri lošim klimatskim uslovima bio je za oko 46 % niži, što bi trebalo da se uzme u obzir u slučaju planiranja raspoložive količine. Procenjeno je da bi energetski potencijal, uzimajući u obzir i očuvanje plodnosti zemljišta, uljane repice mogao da bude 1,1 do 2,0 Mg ha–1. Nadzemna masa žetvenih ostataka može, uz primenu obrade zemljišta bez prevrtanja, da osigura zaštitu zemljišta od erozije vetra i doprinese očuvanju plodnosti zemljišta, organske mase i organskog ugljenika. Žetveni ostaci uljane repice mogu da budu dobra podloga za sprovođenje upravljanja organskom materijom, primenom odgovarajućeg plodoreda, te da se koriste za kompenzovanje organske materije koja se iznosi ubiranjem žetvenih ostataka drugih biljnih vrsta, na primer, pšenice, soje i kukuruza. Buduća istraživanja trebalo bi da budu usmerena ka oceni primenljivosti žetvenih ostataka repice za očuvanje plodnosti zemljišta

INVESTIGATION OF MAIZE COBS CRUSHING - PREPARATION FOR USE AS A FUEL

Maize crop residues have great significance, particularly in developing countries, where the harvest of maize ears and their natural drying is widely applied. After drying and grain threshing, maize cobs are available for energetic use on farmers' yards. Shortcomings for their energetic utilization by combustion, in comparison with wood, are higher contents of potassium, chlorine and nitrogen, and lower ash softening point. Tests in small wood chip boilers showed that the size of maize cobs should be reduced in order to facilitate better combustion and feeding with commonly used screw conveyors. Desirable length of particles should be 1-1.5 of their diameter. Within the framework of the Eureka project, a low-cost maize cobs crusher was developed and tested. It consists of a drum with six rows of knives, stationary comb-like knives and a screen situated below the drum. The test resulted with working parameters that enable appropriate size reduction. Analyses of crushed material showed that over 80% of particles were in the range of 3.15-45 mm, less than 1% smaller than 1 mm, and less than 1% larger than 63 mm. This granulation is comparable with size class P45 for wood chips in accordance with standard DIN CEN/TS 14961. Further investigations should focus on improving the combustion facilities, in order to avoid formation of ash slag, and keeping exhaust gas characteristics within values defined by legislation

Mechanized harvesting and primary processing of Calendula officinalis L. inflorescences

Manual harvesting of marigold (Calendula officinalis L.) inflorescences results in superior quality, but requires enormous manpower. The objectives of the research were to examine the possibility of mechanized harvesting of marigold inflorescences by virtual rotating comb-type chamomile harvester, widely used in South Eastern Europe, and to develop the mechanical separator for the inflorescences from the harvested mass. The impact of coefficient R, ratio of the harvester�s penetration into the inflorescences horizon and the width of inflorescences band (i.e. the average value of the highest and lowest inflorescences span) on the harvest yield, was tested first. Separation was performed by a bespoke separator that uses five cascades of oscillating sieves made of longitudinally situated rods. Influence of oscillation frequencies and rod distances on separation efficiency was investigated. It was found that, for coefficient R value of 1.3, an average of 97% of the total inflorescences yield can be harvested. The proportion of inflorescences with stem length up to 2 cm was 65% and 35% for stems over 2 cm. The result of mechanized harvest was the reduction in both the number of succeeding harvests and the yield, due to bud damages and elimination. The highest separation efficiency was obtained by using 2.7 Hz oscillation frequency and combination of 6/8 mm rods� distances in sieves. After three passes of the harvested mass through the device, approximately 92% of inflorescences were separated. Future investigations should be directed towards solving the issue of mechanical shortening of the inflorescences stems and evaluating the economic viability of mechanized harvesting within the proposed procedur

Mechanized harvesting and primary processing of Calendula officinalis L. inflorescences

Manual harvesting of marigold (Calendula officinalis L.) inflorescences results in superior quality, but requires enormous manpower. The objectives of the research were to examine the possibility of mechanized harvesting of marigold inflorescences by virtual rotating comb-type chamomile harvester, widely used in South Eastern Europe, and to develop the mechanical separator for the inflorescences from the harvested mass. The impact of coefficient R, ratio of the harvester’s penetration into the inflorescences horizon and the width of inflorescences band (i.e. the average value of the highest and lowest inflorescences span) on the harvest yield, was tested first. Separation was performed by a bespoke separator that uses five cascades of oscillating sieves made of longitudinally situated rods. Influence of oscillation frequencies and rod distances on separation efficiency was investigated. It was found that, for coefficient R value of 1.3, an average of 97% of the total inflorescences yield can be harvested. The proportion of inflorescences with stem length up to 2 cm was 65% and 35% for stems over 2 cm. The result of mechanized harvest was the reduction in both the number of succeeding harvests and the yield, due to bud damages and elimination. The highest separation efficiency was obtained by using 2.7 Hz oscillation frequency and combination of 6/8 mm rods’ distances in sieves. After three passes of the harvested mass through the device, approximately 92% of inflorescences were separated. Future investigations should be directed towards solving the issue of mechanical shortening of the inflorescences stems and evaluating the economic viability of mechanized harvesting within the proposed procedure